[The role of reduction of the heart rate in the favorable effect of the beta blockers on myocardial ischemia due to isoprenalin in patients with angina pectoris].

In the patient suffering from angina, the protective effect of oxprenolol in the isoprenaline test is demonstrated by the reduction of disappearance of ischemic-type electrocardiographic alterations and of angina and rhythm disturbances. In our study, these results were obtained in spite of neutralization of the negative chronotropic effect of the beta-blocker through the use of an endo-auricular pacemaker. This points indirectly to the role played by the contractile state of the myocard in catecholamine-induced modifications of the oxygen intake of cardiac muscle.